> "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
> news:5414D698.9030000@electrooptical.net...
>> On 9/13/2014 1:21 PM, John Larkin wrote:
>>> On Fri, 12 Sep 2014 22:52:21 -0400, krw@attt.bizz wrote:
>>>
>>>> On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>>>>
>>>>> I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>>>>> current mirror.
>>>>
>>>> What specs?
>>>>
>>>>> What would you guys in the discrete world recommend as being
>>>>> well-behaved, no peculiarities, etc? (And readily available ;-)
>>>>
>>>> I've been using the MicroChip MCP6294, mainly because they're cheap
>>>> but the specs matter.
>>>
>>> That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
>>> around 40 cents in quantity. (I like singles, usually.) Somewhere
>>> there ought to be a really cheap workhorse opamp, ten cents maybe.
>>>
>>>
>>
>> Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a dual!
>> ;)
>>
>> http://octopart-clicks.com/click/vptrack?ak=68b25f31&sig=077166e&vpid=1
>> 16013415
>>
>> Cheers
>> Phil Hobbs
>>
>
> But the LM358 doesn't use any bias, and so there is crossover distortion at
> the mid point if used in a linear application such as audio. Maybe that's
> not an issue for other applications?
>
> -Bill
For nine cents in onesies, he expects perfection. An arrant varlet,
forsooth. ;)
LM358s and 324s are occasionally useful, but usually in unipolar
applications, true. A figure of merit for a given design is how crappy
an amplifier you can use and have it still work well.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by Bill Bowden●September 15, 20142014-09-15
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:5414D698.9030000@electrooptical.net...
> On 9/13/2014 1:21 PM, John Larkin wrote:
>> On Fri, 12 Sep 2014 22:52:21 -0400, krw@attt.bizz wrote:
>>
>>> On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>>>
>>>> I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>>>> current mirror.
>>>
>>> What specs?
>>>
>>>> What would you guys in the discrete world recommend as being
>>>> well-behaved, no peculiarities, etc? (And readily available ;-)
>>>
>>> I've been using the MicroChip MCP6294, mainly because they're cheap
>>> but the specs matter.
>>
>> That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
>> around 40 cents in quantity. (I like singles, usually.) Somewhere
>> there ought to be a really cheap workhorse opamp, ten cents maybe.
>>
>>
>
> Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a dual!
> ;)
>
> http://octopart-clicks.com/click/vptrack?ak=68b25f31&sig=077166e&vpid=1
> 16013415
>
> Cheers
> Phil Hobbs
>
But the LM358 doesn't use any bias, and so there is crossover distortion at
the mid point if used in a linear application such as audio. Maybe that's
not an issue for other applications?
-Bill
--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
Reply by Phil Hobbs●September 14, 20142014-09-14
On 9/13/2014 11:33 PM, Tim Williams wrote:
> "Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
> news:5414D698.9030000@electrooptical.net...
>> Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
>> dual! ;)
>>
>> http://octopart-clicks.com/click/vptrack?ak=68b25f31&sig=077166e&vpid=1
>> 16013415
>
> Speaking of, I've been looking for "single supply" (includes ground) or
> RRIO chips with higher supply voltage (12V minimum, >16 preferred for
> reliability). Catch is: needs more GBW than an LM358.
>
> Closest I've seen is CA3130, but it seems rather obscure (almost
> everything CA- is utterly obsolete, though Intersil still seems to be
> supporting a few).
I remember those. The CA3140 was more or less the same part, but with a
bipolar totem-pole output stage.
The CA3100 was magic back in about 1980--it was the only amp we could
find that could handle multiple channel PSK data in a 3-MHz bandwidth
with acceptable intermod.
TI makes a bunch of quite reasonable higher-voltage op amps, e.g. the
OPA188/2188/4188 chopamps.
Cheers
Phil Hobbs
>
> There was one or two from TI or LT that meet or exceed (particularly in
> offset), but they're no cheaper.
>
> Decomp or current feedback would be fine (it's for gain ~ 50, GBW >=
> 25MHz), but both are like hens' teeth, or have way too much GBW (video
> amps, etc.).
>
> Tim
>
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by Tim Williams●September 14, 20142014-09-14
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:5414D698.9030000@electrooptical.net...
Speaking of, I've been looking for "single supply" (includes ground) or
RRIO chips with higher supply voltage (12V minimum, >16 preferred for
reliability). Catch is: needs more GBW than an LM358.
Closest I've seen is CA3130, but it seems rather obscure (almost
everything CA- is utterly obsolete, though Intersil still seems to be
supporting a few).
There was one or two from TI or LT that meet or exceed (particularly in
offset), but they're no cheaper.
Decomp or current feedback would be fine (it's for gain ~ 50, GBW >=
25MHz), but both are like hens' teeth, or have way too much GBW (video
amps, etc.).
Tim
--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com
Reply by Phil Hobbs●September 13, 20142014-09-13
On 9/13/2014 8:27 PM, Jim Thompson wrote:
> On Sat, 13 Sep 2014 19:43:20 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> On 9/13/2014 1:21 PM, John Larkin wrote:
>>> On Fri, 12 Sep 2014 22:52:21 -0400, krw@attt.bizz wrote:
>>>
>>>> On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>>>>
>>>>> I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>>>>> current mirror.
>>>>
>>>> What specs?
>>>>
>>>>> What would you guys in the discrete world recommend as being
>>>>> well-behaved, no peculiarities, etc? (And readily available ;-)
>>>>
>>>> I've been using the MicroChip MCP6294, mainly because they're cheap
>>>> but the specs matter.
>>>
>>> That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
>>> around 40 cents in quantity. (I like singles, usually.) Somewhere
>>> there ought to be a really cheap workhorse opamp, ten cents maybe.
>>>
>>>
>>
>> Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
>> dual! ;)
>>
>> http://octopart-clicks.com/click/vptrack?ak=68b25f31&sig=077166e&vpid=1
>> 16013415
>>
>> Cheers
>>
>> Phil Hobbs
>
> But not RRIO.
>
> ...Jim Thompson
>
Picky, picky.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by ●September 13, 20142014-09-13
On Sat, 13 Sep 2014 10:21:49 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:
>On Fri, 12 Sep 2014 22:52:21 -0400, krw@attt.bizz wrote:
>
>>On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>>
>>>I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>>>current mirror.
>>
>>What specs?
>>
>>>What would you guys in the discrete world recommend as being
>>>well-behaved, no peculiarities, etc? (And readily available ;-)
>>
>>I've been using the MicroChip MCP6294, mainly because they're cheap
>>but the specs matter.
>
>That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
>around 40 cents in quantity. (I like singles, usually.) Somewhere
>there ought to be a really cheap workhorse opamp, ten cents maybe.
I'm paying less than that for the quad. Less than half for the single
(though I haven't used any). Yeah, it's a general purpose opamp with
nothing special going for it except its cost. It is R-R I/O, which
command a premium over others. I can get non R-R opamps from NJR for
well under $.10 but they're pretty old-school bipolars. I'm trying to
keep my analog rail under 5V, which kinda dictates R-R.
Reply by Jim Thompson●September 13, 20142014-09-13
On Sat, 13 Sep 2014 19:43:20 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>On 9/13/2014 1:21 PM, John Larkin wrote:
>> On Fri, 12 Sep 2014 22:52:21 -0400, krw@attt.bizz wrote:
>>
>>> On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>>>
>>>> I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>>>> current mirror.
>>>
>>> What specs?
>>>
>>>> What would you guys in the discrete world recommend as being
>>>> well-behaved, no peculiarities, etc? (And readily available ;-)
>>>
>>> I've been using the MicroChip MCP6294, mainly because they're cheap
>>> but the specs matter.
>>
>> That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
>> around 40 cents in quantity. (I like singles, usually.) Somewhere
>> there ought to be a really cheap workhorse opamp, ten cents maybe.
>>
>>
>
>Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
>dual! ;)
>
>http://octopart-clicks.com/click/vptrack?ak=68b25f31&sig=077166e&vpid=1
>16013415
>
>Cheers
>
>Phil Hobbs
But not RRIO.
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Reply by Phil Hobbs●September 13, 20142014-09-13
On 9/13/2014 1:21 PM, John Larkin wrote:
> On Fri, 12 Sep 2014 22:52:21 -0400, krw@attt.bizz wrote:
>
>> On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>>
>>> I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>>> current mirror.
>>
>> What specs?
>>
>>> What would you guys in the discrete world recommend as being
>>> well-behaved, no peculiarities, etc? (And readily available ;-)
>>
>> I've been using the MicroChip MCP6294, mainly because they're cheap
>> but the specs matter.
>
> That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
> around 40 cents in quantity. (I like singles, usually.) Somewhere
> there ought to be a really cheap workhorse opamp, ten cents maybe.
>
>
Already exists. LM358, $0.09 in quantity 1 from Newark. And it's a
dual! ;)
http://octopart-clicks.com/click/vptrack?ak=68b25f31&sig=077166e&vpid=1
16013415
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by John Larkin●September 13, 20142014-09-13
On Fri, 12 Sep 2014 22:52:21 -0400, krw@attt.bizz wrote:
>On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>
>>I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>>current mirror.
>
>What specs?
>
>>What would you guys in the discrete world recommend as being
>>well-behaved, no peculiarities, etc? (And readily available ;-)
>
>I've been using the MicroChip MCP6294, mainly because they're cheap
>but the specs matter.
That looks OK for non-critical stuff. The single MCP6291 in SOT23 is
around 40 cents in quantity. (I like singles, usually.) Somewhere
there ought to be a really cheap workhorse opamp, ten cents maybe.
--
John Larkin Highland Technology, Inc
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
Reply by ●September 12, 20142014-09-12
On Fri, 12 Sep 2014 10:58:49 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>I need a rail-to-rail I/O OpAmp, 5V Vcc is fine, slow speed setting a
>current mirror.
What specs?
>What would you guys in the discrete world recommend as being
>well-behaved, no peculiarities, etc? (And readily available ;-)
I've been using the MicroChip MCP6294, mainly because they're cheap
but the specs matter.